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Publication numberUS7280483 B2
Publication typeGrant
Application numberUS 10/863,183
Publication date9 Oct 2007
Filing date7 Jun 2004
Priority date5 Jun 2003
Fee statusPaid
Also published asEP1629677A1, EP1629677A4, US20040252643, WO2004114690A1, WO2004114690B1
Publication number10863183, 863183, US 7280483 B2, US 7280483B2, US-B2-7280483, US7280483 B2, US7280483B2
InventorsAvinash Joshi
Original AssigneeMeshnetworks, Inc.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
System and method to improve the network performance of a wireless communications network by finding an optimal route between a source and a destination
US 7280483 B2
Abstract
A system and method for calculating an optimal route at a node by making use of routing metrics which if carefully chosen, can provide stability to the network and also provide features like Self Healing and Load Balancing. A Routing metric is calculated as a scalar number based upon a number of factors, such as number of hops, data rate, link quality and device type. Each factor can be determined by evaluation of Hello messages, or other routing messages as required.
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Claims(14)
1. A method for calculating an optimal route between nodes in a wireless ad-hoc multi-hopping peer-to-peer communication network, the method comprising:
when one of the nodes acts as a source node and attempts to send a data packet to another one of the nodes which is a destination node which is not within direct communication with the source node, the source node transmits a route request message;
when other nodes receive the route request message, and one of those other nodes has a route to the destination node, that one of the nodes transmits a route reply message for delivery along a path including those other nodes, the route reply message including a route metric for the route between that one node and the destination node, the route metric including information representing at least one of the following: a number of hops between the source and destination node, a data rate along the route between the source and destination node, link quality along the route between the source and destination node, and information representing the types of nodes along the route between the source and destination node, and each of those other nodes, upon receipt of the route reply message, adds its respective route metric for a route between itself and the node from which it received the route reply message, before delivery of the route reply message to the source node; and
the source node transmits the data packet for delivery to the destination node based on the route reply message.
2. A method as claimed in claim 1, wherein: the source node and destination node are mobile nodes.
3. A method as claimed in claim 1, wherein:
the route request message and route reply message each include respective hop count information and route metric information which are updated each time the respective message is sent from one node to another.
4. A method as claimed in claim 1, wherein:
the route metric includes information representing at least one of the following: a data rate along the route between the source and destination node, and information representing the types of nodes along the route between the source and destination node.
5. A method for calculating an optimal route between a node and a destination node through one or more other nodes including at least one neighbor node in a wireless communication network, the method comprising:
the neighbor node broadcasting a message including a routing metric from the neighbor node to the destination node;
in response to receiving the message, the node calculating a route metric to the destination node through the neighbor node by adding to the route metric in the message its respective route metric for a route between itself and the neighbor node from which it received the message and a bias associated with a type of the neighbor node, and uses this updated route metric as the route metric for the route to the node.
6. A method as claimed in claim 5, wherein:
the message is a routing message.
7. A method as claimed in claim 5, wherein:
the message is a hello message.
8. A method as claimed in claim 5, wherein:
the route metric includes information representing at least one of the following: a data rate along the route between the source and destination nodes, and information representing the types of nodes along the route between the source and destination nodes.
9. A method as claimed in claim 5, wherein:
the message is a periodic message.
10. A system for calculating an optimal route between a node and a destination node through one or more other nodes including at least one neighbor node in a wireless communication network, the system comprising:
the neighbor node, which broadcasts a message including a routing metric from the neighbor node to the destination node; and
the node, comprising:
a controller for calculating a route metric to the destination node through the neighbor node by adding, upon receipt of the message, to the route metric in the message its respective route metric for a route between itself and the neighbor node from which it received the message and a bias associated with a type of the neighbor node, and uses this updated route metric as the route metric for the route to the node.
11. A system as claimed in claim 10, wherein:
the message is a routing message.
12. A system as claimed in claim 10, wherein:
the message is a hello message.
13. A system as claimed in claim 10, wherein:
the route metric includes information representing at least one of the following: a data rate along the route between the source and destination nodes, and information representing the types of nodes along the route between the source and destination nodes.
14. A system as claimed in claim 10, wherein:
the message is a periodic message.
Description

This application claims benefit under 35 U.S.C. § 119(e) from U.S. Provisional Patent Application Ser. No. 60/476,237, filed on Jun. 6, 2003, U.S. Provisional Patent Application Ser. No. 60/546,941, filed on Feb. 24, 2004, and U.S. Provisional Patent Application Ser. No. 60/546,940, filed on Feb. 24, 2004, U.S. Provisional Patent Application Ser. No. 60/476,236, filed on Jun. 6, 2003, and U.S. Provisional Patent Application Ser. No. 60/475,882, filed Jun. 5, 2003, the entire contents of each being incorporated herein by reference

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system and method for improving the network performance of a wireless communication network by finding an optimal route between a source and a destination. An optimal route is chosen by making use of routing metrics which if carefully chosen, can provide stability to the network and also provide features like Self Healing and Load Balancing.

2. Description of the Related Art

Wireless communication networks, such as mobile wireless telephone networks, have become increasingly prevalent over the past decade. These wireless communications networks are commonly referred to as “cellular networks”, because the network infrastructure is arranged to divide the service area into a plurality of regions called “cells”. A terrestrial cellular network includes a plurality of interconnected base stations, or base nodes, that are distributed geographically at designated locations throughout the service area. Each base node includes one or more transceivers that are capable of transmitting and receiving electromagnetic signals, such as radio frequency (RF) communications signals, to and from mobile user nodes, such as wireless telephones, located within the coverage area. The communications signals include, for example, voice data that has been modulated according to a desired modulation technique and transmitted as data packets. As can be appreciated by one skilled in the art, network nodes transmit and receive data packet communications in a multiplexed format, such as time-division multiple access (TDMA) format, code-division multiple access (CDMA) format, or frequency-division multiple access (FDMA) format, which enables a single transceiver at a first node to communicate simultaneously with several other nodes in its coverage area.

In recent years, a type of mobile communications network known as an “ad-hoc” network has been developed. In this type of network, each mobile node is capable of operating as a base station or router for the other mobile nodes, thus eliminating the need for a fixed infrastructure of base stations. Details of an ad-hoc network are set forth in U.S. Pat. No. 5,943,322 to Mayor, the entire content of which is incorporated herein by reference.

More sophisticated ad-hoc networks are also being developed which, in addition to enabling mobile nodes to communicate with each other as in a conventional ad-hoc network, further enable the mobile nodes to access a fixed network and thus communicate with other mobile nodes, such as those on the public switched telephone network (PSTN), and on other networks such as the Internet. Details of these advanced types of ad-hoc networks are described in U.S. Pat. No. 7,072,605 entitled “Ad Hoc Peer-to-Peer Mobile Radio Access System Interfaced to the PSTN and Cellular Networks”, issued on Jul. 4, 2006, in U.S. Pat. No. 6,807,165 entitled “Time Division Protocol for an Ad-Hoc, Peer-to-Peer Radio Network Having Coordinating Channel Access to Shared Parallel Data Channels with Separate Reservation Channel”, issued on Oct. 19, 2004 and in U.S. Pat. No. 6,873,839 entitled “Prioritized-Routing for an Ad-Hoc, Peer-to-Peer, Mobile Radio Access System”, issued on Mar. 29, 2005, the entire content of each being incorporated herein by reference.

As can be appreciated by one skilled in the art, since certain nodes of the ad-hoc network are mobile, it is necessary for the network to maintain connectivity with those nodes. Transmitted data packets typically “hop” from mobile device to mobile device, creating a transmission path, or route, until reaching a final destination. However, transmission paths between mobile devices are often subject to change as devices move, therefore ad-hoc network communication must be able to adapt to achieve optimum performance while addressing the limited capabilities and capacities of mobile individual devices.

In a typical wireless communication network, the number of hops between the source and the destination is used as the routing metric. The lesser the number of hops the better the route. However, this can lead to un-optimal routes, as there can be a better route with more number of hops but better link quality or data rate.

Accordingly, a need exists for a system and method to discover optimal routes between a source and a destination in an efficient way using factors other than hops as the sole metrics.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a system and method for locating optimal routes between a source and destination node using a broad range of Route metrics.

Another object of the present invention is to provide a system and method for calculating Route metrics using Hello messages exchanged in a network.

Another object of the present invention is to provide a system and method for calculating Route metrics using Routing messages, such as Route Request and Route Reply.

These and other objects are substantially achieved by providing a system and method for making use of routing metrics which if carefully chosen, can provide stability to the network and also provide features like Self Healing and Load Balancing. A Routing metric is calculated as a scalar number based upon a number of factors, such as number of hops, data rate, link quality and device type. Each factor can be determined by evaluation of Hello messages, or other routing messages as required.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, advantages and novel features of the invention will be more readily appreciated from the following detailed description when read in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram of an example ad-hoc wireless communications network including a plurality of nodes in accordance with an embodiment of the present invention;

FIG. 2 is a block diagram illustrating an example of a mobile node employed in the network shown in FIG. 1;

FIG. 3 is a conceptual block diagram illustrating an example of a Routing metric computation through Hello packets in accordance with an embodiment of the present invention; and

FIG. 4 is a conceptual block diagram illustrating an example of a Routing metric computation through routing packets in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The embodiments of the present invention described below provide a method and system which improves the network performance of a wireless communication network by finding an optimal route between a source and a destination. An optimal route is the one which either has lower latency and/or higher throughput and/or better utilization of the network resources. This route is chosen by making use of the routing metrics which are described in greater detail below. If carefully chosen, routing metrics can provide stability to the network and also provide features like Self Healing and Load Balancing.

In a typical wireless communication network, such as network 100 of FIG. 1, number of hops between the source and the destination is typically used as the routing metric. The lesser the number of hops the better the route. As noted above, this can lead to un-optimal routes, as there can be a better route with more number of hops but better link quality or data rate.

FIG. 1 is a block diagram illustrating an example of an ad-hoc packet-switched wireless communications network 100 employing an embodiment of the present invention. Specifically, the network 100 includes a plurality of mobile wireless user terminals 102-1 through 102-n (referred to generally as nodes 102 or mobile nodes 102), and can, but is not required to, include a fixed network 104 having a plurality of access points 106-1, 106-2, . . . 106-n (referred to generally as nodes 106 or access points 106), for providing nodes 102 with access to the fixed network 104. The fixed network 104 can include, for example, a core local access network (LAN), and a plurality of servers and gateway routers to provide network nodes with access to other networks, such as other ad-hoc networks, the public switched telephone network (PSTN) and the Internet. The network 100 further can include a plurality of fixed routers 107-1 through 107-n (referred to generally as nodes 107 or fixed routers 107) for routing data packets between other nodes 102, 106 or 107. It is noted that for purposes of this discussion, the nodes discussed above can be collectively referred to as “nodes 102, 106 and 107”, or simply “nodes”.

As can be appreciated by one skilled in the art, the nodes 102, 106 and 107 are capable of communicating with each other directly, or via one or more other nodes 102, 106 or 107 operating as a router or routers for packets being sent between nodes, as described in U.S. Pat. No. 5,943,322 to Mayor, and in U.S. Pat. Nos. 7,072,650, 6,807,165 and 6,873,839 referenced above.

As shown in FIG. 2, each node 102, 106 and 107 includes a transceiver, or modem 108, which is coupled to an antenna 110 and is capable of receiving and transmitting signals, such as packetized signals, to and from the node 102, 106 or 107, under the control of a controller 112. The packetized data signals can include, for example, voice, data or multimedia information, and packetized control signals, including node update information.

Each node 102, 106 and 107 further includes a memory 114, such as a random access memory (RAM) that is capable of storing, among other things, routing information pertaining to itself and other nodes in the network 100. As further shown in FIG. 2, certain nodes, especially mobile nodes 102, can include a host 116 which may consist of any number of devices, such as a notebook computer terminal, mobile telephone unit, mobile data unit, or any other suitable device. Each node 102, 106 and 107 also includes the appropriate hardware and software to perform Internet Protocol (IP) and Address Resolution Protocol (ARP), the purposes of which can be readily appreciated by one skilled in the art. The appropriate hardware and software to perform transmission control protocol (TCP) and user datagram protocol (UDP) may also be included.

As noted above, number of hops between a source node and a destination node is typically used as the routing metric for selecting a route between nodes in a network such as network 100 of FIG. 1. This can lead to un-optimal routes, as there can be a better route with more number of hops but better link quality or data rate. The embodiments described below include the usage of other such metrics.

The routing metric is a scalar number which represents the cost between the source and the destination. The higher the cost, the worse is the route. The different factors which determines the cost can include, but are not limited to the following:

    • 1. Number of hops between the source and the destination;
    • 2. Data rate along the route from the source and the destination;
    • 3. Link quality along the route from the source and the destination; and
    • 4. Type of the device present as intermediate node between the source and the destination.

The use of these factors can be justified for the following category of reasons.

Number of Hops

In any network, the delay incurred by a packet at each hop is a function of the processing and queuing delays at the transmitting node and the transmission, including medium access, and propagation delays over the link. Thus, in a multihop network reducing the number of hops in a route may significantly reduce the end-to-end delays experienced by packets traversing the route. Routing backbones consisting of small numbers of long-range links are frequently employed to provide low-delay, high-speed connectivity between distant nodes in large networks.

In multi-hop wireless networks, the need for reduced route length is even greater than in wireline networks because of the larger delays likely to be experienced at each hop. These delays can include medium access delay resulting from contention for the shared channel, transmission delay resulting from increased packet size for error-control or direct-sequence spread-spectrum coding, retransmission delay resulting from link layer Automatic Repeat Request (ARQ) protocols for reliability over error-prone links, and radio-dependent delay such as that incurred when switching between transmission and reception modes.

Data Rate

A node could be using different data rate to different neighbors depending upon the reliability for the link. Given a choice, a node should use the highest data rate available to increase the throughput and thus, data rate should be a factor in the overall routing metric.

Link Quality

The quality of the link which can be a combined value of the RSSI level, Bit Error Rate, PDSQ values, timeouts and so forth, should also be a part of the metric to allow routing to pick a good quality link over a bad one.

Device Type

There are three different device types in a wireless network, such as a Mesh Network, namely subscriber devices (SD), wireless routers (WR) and intelligent access points (IAP). Given a choice of intermediate node (i.e. not the destination node) devices should choose a WR before an SD or an IAP so that devices do not drain out batteries of other SD devices and also do not make an IAP busy. Similarly devices should use an IAP before an SD as intermediate nodes for the same reason. There can be several other devices in such a network and hence type of device should be an important part of the overall routing metrics. An example of this is described in greater detail below.

The devices used in this kind of network typically have a module called an ATP. This module reports link quality for all MAC addresses that a node has communicated by exchanging data messages. The ATP can also provide the current data rate which is used to communicate with this neighbor. The link quality/data rate can be communicated to the other module, typically routing as a scalar number. A look up table can then be used to find out the reliability of the link and the data rate used. Additional details of an ATP and link quality are discussed in U.S. Pat. No. 6,904,021, entitled “System and Method for Providing Adaptive Control of Transmit Power and Data Rate in Ad-Hoc Networks”, issued on Jun. 7, 2005; in U.S. Patent Publication Number 20040260808 entitled “A Method to Provide a Measure of Link Reliability to a Routing Protocol in an Ad Hoc Network”, published Oct. 23, 2004; in U.S. Patent Publication Number 20040246935, entitled “System and Method for Characterizing the Quality of a Link in a Wireless Network”, published on Dec. 09, 2004, the entire contents of each being incorporated herein by reference.

The following example shows a way to calculate a routing metric which is used in a system using a modified On Demand routing protocol. Details of such routing methods are further discussed in U.S. Patent Application Publication No. 20040143842 entitled “System and Method for Achieving Continuous Connectivity to an Access Point or Gateway in a Wireless Network Following an On-Demand Routing Protocol, and To Perform Smooth Handoff Of Mobile Terminals,” published on Jul. 22, 2004; in U.S. Pat. No. 7,061,925 entitled “System and Method to Improve the Overall Performance of a Wireless Communication Network”, issued on Jun. 13, 2006; and in U.S. Patent Application Publication No. 20040258040 entitled “System and Method to Maximize Channel Utilization in a Multi-Channel Wireless Communication Network”, published on Dec. 23, 2004, the entire content of each being incorporated herein by reference. A Route Metric computation in accordance with an embodiment of the present invention is described in greater detail below.

In infrastructure mode, nodes find out about the routing metric to any destination other than an IAP through exchange of routing packets. Routing metrics to an IAP can be found by exchange of routing packets as well as hearing the hello packets from the neighbors. In case there is a difference in the routing metrics which is being computed from hello messages and that from routing packets, the hello message information is used. The following are Route metrics computation examples in accordance with an embodiment of the present invention.

Route Metrics to the LAP Through Hello Messages

A source node, following the protocol referred above, knows about the routes to the IAP and the route metric to reach it from its neighbors, which periodically broadcast this information in the Hellos. This metric is then added to the metric to the particular neighbor advertising the IAP. A bias is also added to differentiate between different types of nodes and prefer one over another. Mathematically, this can be represented in the following Equation (1) below.
R sd =R sn +R nd+Next Hop Bias  (1)
where Rsd=Route metric between source and destination, Rsn=Route metric between source and next hop, Rnd=Route metric between next hop and destination (which next hop reported), and Rsn i.e. Routing metric to the next hop or neighbor is calculated using the following Equation (2).

Rsn = A constant number + Different biases based on
the quality of the link and
the data rate

Routing metric to destinations other than neighbors are calculated using the Equation (1) where an additional next hop bias is added based on the type of neighbor.

In words the equation can be written as:
Routing metric to the destination=Routing metric to the next hop/neighbor+Routing metric from the next hop/neighbor to the Destination+Biased based on the type of next hop/neighbor

The following example shown in FIG. 3 is presented to clarify the procedure. FIG. 3 is an example illustrating a Routing Metric Computation through hello packets in accordance with an embodiment of the present invention.

In this example ‘s’ 120 is the current node which is trying to find the route to the destination, which is usually IAP, and ‘n’ 130 is its neighboring node advertising its route to the destination through hello packets. The hello packet 140 contains the routing metric from the neighbor to the destination which is Rnd. The routing metrics from ‘s’ to ‘n’ is Rsn and from ‘n’ to ‘s’ is Rns. The link may not be uniform and hence these values can be different. On receiving such a hello message, node ‘s’ uses the Equation (1) above to find the routing metric to the destination which is Rsd. The nodes s and n can be any device (i.e. SD, WR or IAP). In case of IAP the advertised metric is zero.

Route Metrics to Other Destinations Through Routing Messages

Route Request (RREQ) and Route Reply (RREP) are generally used in this kind of network to get routes to different nodes. These messages have a field called “Routing Metrics” and “Hop Count” which gets updated with each hop traveled. When a node initiates a Route Request it puts zero in both of these fields. Now this packet can be received by an intermediate node or a destination. In both the cases, the receiving node creates a route back to the source of the RREQ after adding their “routing metric to the neighbor” in the “Routing Metrics” field and “1” in the “Hop Count” field. It then forwards the RREQ or replies back with a RREP message as specified in the protocol. If it forwards the RREQ the receiving node does the same thing as explained before (i.e. adding route to the source route and adding the “routing metric to the neighbor” in the “Routing Metrics” field of RREQ packet and hence getting the routing metric to the source address).

The node can reply only if it has a valid route to the destination or it itself is the destination. If the node is an intermediate node, it puts the routing metric from the routing table to the field in the RREP. On receiving this RREP a node adds its “routing metric to the neighbor” who forwarded/sent this RREP. And hence has the complete routing metric to the destination concerned. RREP is forwarded to the source if the current node is not the source. Similar action is performed when the replying node is destination, except the fact that it puts zero in the “Routing Metrics” field in the RREP. This value is modified as the RREP traverses through different nodes in the way.

The following example shown in FIG. 4 is presented to clarify the procedure. FIG. 4 is an example illustrating a Routing Metric Computation through routing packets in accordance with an embodiment of the present invention.

There are four nodes shown in FIG. 4, node A 150, B 160, C 170 and D 180. The routing metrics between them are also shown in the diagram. RXY represent the routing metric between node X and Y. Note that due to non symmetry involved in wireless links, RXY can be different from RYX. If node A wants to communicate with node D, it initiates a Route Request packet with “Routing Metrics” field set to zero. When this packet is received by node B, it adds its “routing metric to the neighbor” who forwarded the RREQ packet, in this case it is A itself, to the “Routing metrics” field in the RREQ packet and creates/updates a route to the source (i.e. node A) following the routing protocol. In this example, B will add RBA and zero (the current value stored in the “Routing Metrics” field) to get the routing metric to A. If it doesn't know the route to D, it forwards the RREQ packet which has RBA now in the “Routing Metrics” field. On receiving this packet, C does the same thing and adds RCB to RBA to get the routing metric to A. Hence it calculated the routing metric to A as: RCA=RBA+RCB.

If in the example of FIG. 4, assume that C has a “fresh enough” route to D, that is, it has an unexpired route with routing metric RCD. So it replies to the RREQ packet, and to do so it puts the routing metrics RCD in the “Routing Metrics” field of RREP packet and unicasts the packet to node B. On receiving such a packet node B adds its routing metric to its neighbor, which forwarded the RREP packet to it, to the “Routing Metrics” field in the RREP. In this case it will add RBC to RCD which was already present in the field. Hence it calculated the routing metric to D as: RBD=RBC+RCD

A similar procedure can be used by node A when it finally receives the RREP. Hence it has the routing metric to node D as: RAD=RAB+RBC+RCD

A comparison of the above Routing Metric calculations is described below. Given a choice, a node should use the route with minimum route metric associated with it. The Neighbor Handling sub-module maintains a list of routes in the order of increasing route metric to the IAP. The route appearing earlier in this list is given preference over one coming later.

There can be several variations to this approach, for example, some additional bias or hysteresis can be added to prevent oscillations of routes. The “bias” can be a constant value or a function of something like metrics itself or number of hops. The use of bias is explained in the following example.

If in this example a node has a valid route to an IAP and has a metric “x” associated with it, to avoid oscillations it should not try to establish a new route unless it offers a metric which is “y” (bias) less then the current one. A still higher bias can be used if the route is towards some other IAP.

In addition to the metrics identified above, still other metrics can be used, such as battery life, bandwidth, congestion and so forth. Any such category of metrics, including the four discussed above, can be used and propagated as described above, such as in the hello message.

Although only a few exemplary embodiments of the present invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US449419221 Jul 198215 Jan 1985Sperry CorporationHigh speed bus architecture
US46176562 Jan 198614 Oct 1986Tokyo Shibaura Denki Kabushiki KaishaInformation transmission system with modems coupled to a common communication medium
US473637129 Dec 19865 Apr 1988Nec CorporationSatellite communications system with random multiple access and time slot reservation
US474235717 Sep 19863 May 1988Rackley Ernie CStolen object location system
US474713017 Dec 198524 May 1988American Telephone And Telegraph Company, At&T Bell LaboratoriesResource allocation in distributed control systems
US49105213 Aug 198120 Mar 1990Texas Instruments IncorporatedDual band communication receiver
US50349613 Jun 198823 Jul 1991Software Sciences LimitedArea communications system
US506891629 Oct 199026 Nov 1991International Business Machines CorporationCoordination of wireless medium among a plurality of base stations
US523163418 Dec 199127 Jul 1993Proxim, Inc.Medium access protocol for wireless lans
US523360428 Apr 19923 Aug 1993International Business Machines CorporationMethods and apparatus for optimum path selection in packet transmission networks
US524154223 Aug 199131 Aug 1993International Business Machines CorporationBattery efficient operation of scheduled access protocol
US531756618 Aug 199331 May 1994Ascom Timeplex Trading AgLeast cost route selection in distributed digital communication networks
US53924508 Jan 199221 Feb 1995General Electric CompanySatellite communications system
US541265410 Jan 19942 May 1995International Business Machines CorporationHighly dynamic destination-sequenced destination vector routing for mobile computers
US54247479 Apr 199313 Jun 1995Thomson-CsfProcess and system for determining the position and orientation of a vehicle, and applications
US55027221 Aug 199426 Mar 1996Motorola, Inc.Method and apparatus for a radio system using variable transmission reservation
US55174913 May 199514 May 1996Motorola, Inc.Method and apparatus for controlling frequency deviation of a portable transceiver
US55554257 Mar 199010 Sep 1996Dell Usa, L.P.Multi-master bus arbitration system in which the address and data lines of the bus may be separately granted to individual masters
US555554017 Feb 199510 Sep 1996Sun Microsystems, Inc.ASIC bus structure
US557252820 Mar 19955 Nov 1996Novell, Inc.Mobile networking method and apparatus
US561521211 Sep 199525 Mar 1997Motorola Inc.Method, device and router for providing a contention-based reservation mechanism within a mini-slotted dynamic entry polling slot supporting multiple service classes
US56180458 Feb 19958 Apr 1997Kagan; MichaelInteractive multiple player game system and method of playing a game between at least two players
US562173218 Apr 199515 Apr 1997Nec CorporationAccess method and a relay station and terminals thereof
US562349515 Jun 199522 Apr 1997Lucent Technologies Inc.Portable base station architecture for an AD-HOC ATM lan
US562797620 Mar 19956 May 1997Advanced Micro Devices, Inc.Crossing transfers for maximizing the effective bandwidth in a dual-bus architecture
US56318971 Oct 199320 May 1997Nec America, Inc.Apparatus and method for incorporating a large number of destinations over circuit-switched wide area network connections
US564457616 May 19951 Jul 1997International Business Machines CorporationMedium access control scheme for wireless LAN using a variable length interleaved time division frame
US565275126 Mar 199629 Jul 1997Hazeltine CorporationArchitecture for mobile radio networks with dynamically changing topology using virtual subnets
US568039216 Jan 199621 Oct 1997General Datacomm, Inc.Multimedia multipoint telecommunications reservation systems
US568479425 Jan 19964 Nov 1997Hazeltine CorporationValidation of subscriber signals in a cellular radio network
US568719422 Apr 199311 Nov 1997Interdigital Technology CorporationSubscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or a plurality of RF channels
US569690329 Apr 19949 Dec 1997Norand CorporationHierarchical communications system using microlink, data rate switching, frequency hopping and vehicular local area networking
US57012942 Oct 199523 Dec 1997Telefonaktiebolaget Lm EricssonSystem and method for flexible coding, modulation, and time slot allocation in a radio telecommunications network
US570642814 Mar 19966 Jan 1998Lucent Technologies Inc.Multirate wireless data communication system
US571768910 Oct 199510 Feb 1998Lucent Technologies Inc.Data link layer protocol for transport of ATM cells over a wireless link
US574548329 Sep 199528 Apr 1998Ricoh Company, Ltd.Wireless computer network communication system and method having at least two groups of wireless terminals
US577487626 Jun 199630 Jun 1998Par Government Systems CorporationManaging assets with active electronic tags
US578154030 Jun 199514 Jul 1998Hughes ElectronicsDevice and method for communicating in a mobile satellite system
US57870803 Jun 199628 Jul 1998Philips Electronics North America CorporationMethod and apparatus for reservation-based wireless-ATM local area network
US579415426 Jul 199611 Aug 1998Motorola, Inc.Communications system and method of operation
US579673228 Mar 199618 Aug 1998Cisco Technology, Inc.Architecture for an expandable transaction-based switching bus
US57967415 Mar 199618 Aug 1998Nippon Telegraph And Telephone CorporationATM bus system
US580559326 Sep 19958 Sep 1998At&T CorpRouting method for setting up a service between an origination node and a destination node in a connection-communications network
US580584226 Sep 19958 Sep 1998Intel CorporationApparatus, system and method for supporting DMA transfers on a multiplexed bus
US58059771 Apr 19968 Sep 1998Motorola, Inc.Method and apparatus for controlling transmissions in a two-way selective call communication system
US580951820 May 199615 Sep 1998Dallas Semiconductor CorporationCommand/data transfer protocol for one-wire-bus architecture
US582230915 Jun 199513 Oct 1998Lucent Technologies Inc.Signaling and control architecture for an ad-hoc ATM LAN
US58449059 Jul 19961 Dec 1998International Business Machines CorporationExtensions to distributed MAC protocols with collision avoidance using RTS/CTS exchange
US58450973 Jun 19961 Dec 1998Samsung Electronics Co., Ltd.Bus recovery apparatus and method of recovery in a multi-master bus system
US58570842 Oct 19965 Jan 1999Klein; Dean A.Hierarchical bus structure access system
US587035021 May 19979 Feb 1999International Business Machines CorporationHigh performance, high bandwidth memory bus architecture utilizing SDRAMs
US587772425 Mar 19972 Mar 1999Trimble Navigation LimitedCombined position locating and cellular telephone system with a single shared microprocessor
US58810951 May 19979 Mar 1999Motorola, Inc.Repeater assisted channel hopping system and method therefor
US58813721 Dec 19959 Mar 1999Lucent Technologies Inc.Radio communication device and method
US588699215 Apr 199723 Mar 1999Valtion Teknillinen TutkimuskeskusFrame synchronized ring system and method
US589656123 Dec 199620 Apr 1999Intermec Ip Corp.Communication network having a dormant polling protocol
US590355920 Dec 199611 May 1999Nec Usa, Inc.Method for internet protocol switching over fast ATM cell transport
US59096515 May 19971 Jun 1999Lucent Technologies Inc.Broadcast short message service architecture
US593695318 Dec 199710 Aug 1999Raytheon CompanyMulti-mode, multi-channel communication bus
US594332224 Apr 199624 Aug 1999Itt Defense, Inc.Communications method for a code division multiple access system without a base station
US5987011 *30 Aug 199616 Nov 1999King's CollegeRouting method for Ad-Hoc mobile networks
US59870338 Sep 199716 Nov 1999Lucent Technologies, Inc.Wireless lan with enhanced capture provision
US59912794 Dec 199623 Nov 1999Vistar Telecommunications Inc.Wireless packet data distributed communications system
US60288536 Jun 199722 Feb 2000Telefonaktiebolaget Lm EricssonMethod and arrangement for radio communication
US60292173 Oct 199422 Feb 2000International Business Machines CorporationQueued arbitration mechanism for data processing system
US603454214 Oct 19977 Mar 2000Xilinx, Inc.Bus structure for modularized chip with FPGA modules
US60440626 Dec 199628 Mar 2000Communique, LlcWireless network system and method for providing same
US604733020 Jan 19984 Apr 2000Netscape Communications CorporationVirtual router discovery system
US605259430 Apr 199718 Apr 2000At&T Corp.System and method for dynamically assigning channels for wireless packet communications
US605275214 Nov 199618 Apr 2000Daewoo Telecom Ltd.Hierarchical dual bus architecture for use in an electronic switching system employing a distributed control architecture
US606462631 Jul 199816 May 2000Arm LimitedPeripheral buses for integrated circuit
US606729123 Sep 199723 May 2000Lucent Technologies Inc.Wireless local area network with enhanced carrier sense provision
US606729728 Jun 199623 May 2000Symbol Technologies, Inc.Embedded access point supporting communication with mobile unit operating in power-saving mode
US607856628 Apr 199820 Jun 2000Genesys Telecommunications Laboratories, Inc.Noise reduction techniques and apparatus for enhancing wireless data network telephony
US610471222 Feb 199915 Aug 2000Robert; Bruno G.Wireless communication network including plural migratory access nodes
US610873810 Jun 199722 Aug 2000Vlsi Technology, Inc.Multi-master PCI bus system within a single integrated circuit
US61155808 Sep 19985 Sep 2000Motorola, Inc.Communications network having adaptive network link optimization using wireless terrain awareness and method for use therein
US612269017 Apr 199819 Sep 2000Mentor Graphics CorporationOn-chip bus architecture that is both processor independent and scalable
US613088120 Apr 199810 Oct 2000Sarnoff CorporationTraffic routing in small wireless data networks
US613230629 Mar 199617 Oct 2000Cisco Systems, Inc.Cellular communication system with dedicated repeater channels
US61479752 Jun 199914 Nov 2000Ac Properties B.V.System, method and article of manufacture of a proactive threhold manager in a hybrid communication system architecture
US616369915 Sep 199719 Dec 2000Ramot University Authority For Applied Research And Industrial Development Ltd.Adaptive threshold scheme for tracking and paging mobile users
US617833719 Jun 199723 Jan 2001Qualcomm IncorporatedWireless telecommunications system utilizing CDMA radio frequency signal modulation in conjuction with the GSM A-interface telecommunications network protocol
US61920537 Sep 199520 Feb 2001Wireless Networks, Inc.Enhanced adjacency detection protocol for wireless applications
US619223027 Sep 199320 Feb 2001Lucent Technologies, Inc.Wireless data communication system having power saving function
US62088701 Jun 199927 Mar 2001Lucent Technologies Inc.Short message service notification forwarded between multiple short message service centers
US622246325 Jun 199824 Apr 2001Lucent Technologies, Inc.Vehicle communication network
US622250414 Jan 200024 Apr 2001Omnipoint CorporationAdjustable antenna mount with rotatable antenna brackets for PCS and other antennas
US622324031 Jan 200024 Apr 2001Lsi Logic CorporationBus bridge architecture for a data processing system capable of sharing processing load among a plurality of devices
US624029430 May 199729 May 2001Itt Manufacturing Enterprises, Inc.Mobile radio device having adaptive position transmitting capabilities
US624687526 Mar 199912 Jun 2001Bell Atlantic Network Services, Inc.Use of cellular digital packet data (CDPD) communications to convey system identification list data to roaming cellular subscriber stations
US624951627 Jan 200019 Jun 2001Edwin B. BrownriggWireless network gateway and method for providing same
US62757078 Oct 199914 Aug 2001Motorola, Inc.Method and apparatus for assigning location estimates from a first transceiver to a second transceiver
US628589224 Nov 19984 Sep 2001Philips Electronics North America Corp.Data transmission system for reducing terminal power consumption in a wireless network
US630455624 Aug 199816 Oct 2001Cornell Research Foundation, Inc.Routing and mobility management protocols for ad-hoc networks
US632730025 Oct 19994 Dec 2001Motorola, Inc.Method and apparatus for dynamic spectrum allocation
US63490917 Nov 200019 Feb 2002Itt Manufacturing Enterprises, Inc.Method and apparatus for controlling communication links between network nodes to reduce communication protocol overhead traffic
US63492103 Nov 200019 Feb 2002Itt Manufacturing Enterprises, Inc.Method and apparatus for broadcasting messages in channel reservation communication systems
US635987228 Oct 199719 Mar 2002Intermec Ip Corp.Wireless personal local area network
US6363319 *31 Aug 199926 Mar 2002Nortel Networks LimitedConstraint-based route selection using biased cost
US63665684 Oct 19952 Apr 2002Interdigital Technology CorporationTransfer station for wireless telephone distribution system with time and space diversity transmission
US6633544 *24 Jun 199914 Oct 2003At&T Corp.Efficient precomputation of quality-of-service routes
US6646989 *20 Mar 199911 Nov 2003Lucent Technologies Inc.Hop-by-hop routing with node-dependent topology information
US6704293 *6 Dec 19999 Mar 2004Telefonaktiebolaget Lm Ericsson (Publ)Broadcast as a triggering mechanism for route discovery in ad-hoc networks
US6728484 *7 Sep 199927 Apr 2004Nokia CorporationMethod and apparatus for providing channel provisioning in optical WDM networks
US6791949 *28 Apr 200014 Sep 2004Raytheon CompanyNetwork protocol for wireless ad hoc networks
US6813272 *16 Jun 20002 Nov 2004Korea Telecommunication AuthorityQoS-based routing method
US6940832 *17 Jan 20036 Sep 2005The Research Foundation Of The City University Of New YorkRouting method for mobile infrastructureless network
US6961310 *8 Aug 20021 Nov 2005Joseph Bibb CainMultiple path reactive routing in a mobile ad hoc network
US6963927 *29 Aug 20008 Nov 2005Lucent Technologies Inc.Method and apparatus for computing the shortest path between nodes based on the bandwidth utilization link level
US7007102 *29 Apr 200228 Feb 2006Harris CorporationAdmission control in a mobile ad hoc network
US7027426 *5 Aug 200211 Apr 2006Harris CorporationMulti-channel mobile ad hoc network
US7068600 *29 Apr 200227 Jun 2006Harris CorporationTraffic policing in a mobile ad hoc network
US7111074 *24 Jul 200119 Sep 2006Pluris, Inc.Control method for data path load-balancing on a data packet network
US7159035 *25 Sep 20022 Jan 2007Nokia CorporationUnified routing scheme for ad-hoc internetworking
US7177295 *8 Mar 200213 Feb 2007Scientific Research CorporationWireless routing protocol for ad-hoc networks
US20020061001 *24 Aug 200123 May 2002The Regents Of The University Of CaliforniaDynamic source tracing (DST) routing protocol for wireless networks
US20030026268 *11 Mar 20026 Feb 2003Siemens Technology-To-Business Center, LlcCharacteristic routing
US20030118027 *26 Dec 200126 Jun 2003Byoung-Joon LeeMulti-constraint routing system and method
US20030179718 *20 Mar 200325 Sep 2003Nec CorporationRoute selection in a communications network using combined values of metrics of different characteristics
US20040029553 *8 Aug 200212 Feb 2004Harris CorporationMultiple path reactive routing in a mobile ad hoc network
US20040203820 *29 Apr 200214 Oct 2004Harris CorporationAllocating channels in a mobile ad hoc network
US20040233847 *5 May 200425 Nov 2004City University Of New YorkRouting system for establishing optimal route in wireless personal area network (WPAN) and method thereof
US20040233855 *19 May 200325 Nov 2004Gutierrez Jose A.Ad-hoc network and method of routing communications in a communication network
US20040246900 *3 Jun 20039 Dec 2004Palo Alto Research Center, IncorporatedLearning-based strategies for message-initiated constraint-based routing
Non-Patent Citations
Reference
1Ad Kamerman and Guido Aben, "Net Throughput with IEEE 802.11 Wireless LANs", no date.
2Andras G. Valko, "Cellular IP: A New Approach to Internet Host Mobility," Jan. 1999, ACM Computer Communication Review.
3Benjamin B. Peterson, Chris Kmiecik, Richard Hartnett, Patrick M. Thompson, Jose Mendoza and Hung Nguyen, "Spread Spectrum Indoor Geolocation," Aug. 1998, Navigation: Journal of the Institute of Navigation, vol. 45, No. 2, Summer 1998.
4C. David Young, "USAP: A Unifying Dynamic Distributed Multichannel TDMA Slot Assignment Protocol", no date.
5Chip Elliott and Bob Heile, "Self-Organizing, Self-Healing Wireless Networks," 2000 IEEE, no date.
6George Vardakas and Wendell Kishaba, "QoS Networking With Adaptive Link Control and Tactical Multi-Channel Software Radios", no date.
7J. R. McChesney and R.J. Saulitis, "Optimization of an Adaptive Link Control Protocol for Multimedia Packet Radio Networks", no date.
8J.J. Garcia-Luna-Aceves and Asimakis Tzamaloukas, "Reversing the Collision-Avoidance Handshake in Wireless Networks", no date.
9J.J. Garcia-Luna-Aceves and Ewerton L. Madruga, "The Core-Assisted Mesh Protocol," Aug. 1999, IEEE Journal on Selected Areas in Communications, vol. 17, No. 8.
10J.J. Garcia-Luna-Aceves and Marcelo Spohn, "Transmission-Efficient Routing in Wireless Networks Using Link-State Information", no date.
11Josh Broch, David A. Maltz, David B. Johnson, Yih-Chun Hu and Jorjeta Jetcheva, "A Performance Comparison of Multi-Hop Wireless Ad Hoc Network Routing Protocols," Oct. 25-30, 1998, Proceedings of the 4<SUP>th </SUP>Annual ACM/IEEE International Conference on Mobile Computing and Networking.
12Martha E. Steenstrup, "Dynamic Multipoint Virtual Circuits for Multimedia Traffic in Multihop Mobile Wireless Networks", no date.
13Ram Ramanathan and Martha E. Steenstrup, "Hierarchically-Organized, Multihop Mobile Wireless Networks for Quality-of-Service Support", no date.
14Ram Ramanathan and Regina Rosales-Hain, "Topology Control of Multihop Wireless Networks Using Transmit Power Adjustment", no date.
15Richard North, Dale Bryan and Dennis Baker, "Wireless Networked Radios: Comparison of Military, Commercial and R&D Protocols," Feb. 28-Mar. 3, 1999, 2<SUP>nd </SUP>Annual UCSD Conference on Wireless Communications, San Diego, CA.
16Wong et al., "A Pattern Recognition System for Handoff Algorithms," Jul. 2000, IEEE Journal on Selected Areas in Communications, vol. 18, No. 7.
17Wong, et al., "Soft Handoffs in CDMA Mobile Systems," Dec. 1997, IEEE Personal Communications.
18Zhenya Tang and J.J. Garcia-Luna-Aceves, "Collision-Avoidance Transmission Scheduling for Ad-Hoc Networks", no date.
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7412245 *1 Nov 200512 Aug 2008Alpha Networks Inc.Dynamic wireless meshing network for supporting load balance and flow control
US7450521 *11 Feb 200511 Nov 2008Samsung Electronics Co., Ltd.Cost-based routing using backoff scheme
US7486627 *3 Jun 20033 Feb 2009Palo Alto Research Center IncorporatedTime-aware strategy for message-initiated constraint-based routing
US7570628 *6 May 20054 Aug 2009Intel CorporationMethods and apparatus for providing a dynamic on-demand routing protocol
US7577107 *3 Jun 200318 Aug 2009Palo Alto Research Center IncorporatedProtocol specification for message-initiated constraint-based routing
US7577108 *3 Jun 200318 Aug 2009Palo Alto Research Center IncorporatedLearning-based strategies for message-initiated constraint-based routing
US7606176 *22 Jun 200520 Oct 2009Meshnetworks, Inc.System and method to improve the performance of an on demand routing protocol in a wireless network
US764348324 Nov 20045 Jan 2010Microsoft CorporationSystem and method for using a hop limited cast for internet egress point selection
US7649899 *29 Nov 200419 Jan 2010Microsoft CorporationSystem and method for dynamic egress routing through a single default gateway in a mesh network
US7706282 *25 Jun 200327 Apr 2010Leping HuangBluetooth personal area network routing protocol optimization using connectivity metric
US771539524 Nov 200411 May 2010Microsoft CorporationSystem and method for expanding the range of a mesh network
US7764635 *26 Apr 200527 Jul 2010Telcordia Technologies, Inc.Cross-layer self-healing in a wireless ad-hoc network
US7869809 *13 May 200511 Jan 2011Intel CorporationRadio resource measurement and estimation
US78994838 Oct 20071 Mar 2011Honeywell International Inc.Method and system for performing distributed outer loop power control in wireless communication networks
US7995501 *16 Jan 20089 Aug 2011Firetide, Inc.Route optimization for on-demand routing protocols for mesh networks
US801433727 Oct 20086 Sep 2011Motorola Solutions, Inc.Method and system for wireless multi-hopping communication
US8085672 *8 Jul 200527 Dec 2011Honeywell International Inc.Wireless routing implementation
US810738725 Mar 200831 Jan 2012Honeywell International Inc.Method to operate a wireless network having a predictable and stable performance
US8155059 *5 Jun 200910 Apr 2012Oki Electric Industry Co., Ltd.Wireless communications connection control method
US820027020 Aug 200712 Jun 2012Honeywell International Inc.Method for adusting power at a node
US8294568 *10 Jul 200723 Oct 2012Venture Corporation LimitedWireless mine tracking, monitoring, and rescue communications system
US8509152 *5 Nov 200813 Aug 2013Electronics And Telecommunications Research InstituteMethod and apparatus for routing in wireless network
US8599743 *15 Nov 20103 Dec 2013Ricoh Company, Ltd.Method, apparatus, and system for reducing power consumption in a mesh network
US20090303931 *5 Jun 200910 Dec 2009Oki Electric Industry Co., Ltd.Wireless communications connection control method
US20110116402 *15 Nov 201019 May 2011Ricoh Company, Ltd.Method, apparatus, and system for reducing power consumption in a mesh network
US20110164565 *5 Nov 20087 Jul 2011Nam Kyung LeeMethod and apparatus for routing in wireless network
US20120176931 *8 Aug 201112 Jul 2012Jorjeta JetchevaRoute optimization for on-demand routing protocols for mesh networks
WO2004064303A213 Jan 200429 Jul 2004Meshnetworks IncMethod for continuous connectivity to an access point in a wireless network
WO2006052715A23 Nov 200518 May 2006Avinash JoshiSystem and method to decrease the route convergence time and find optimal routes in a wireless communication network
Classifications
U.S. Classification370/238, 709/241, 370/390, 370/232, 370/349, 370/312, 370/230.1
International ClassificationH04L12/56, H04B7/005, H04L12/28, H04W52/46
Cooperative ClassificationH04W52/46, H04W40/02, H04L45/127, H04L45/26
European ClassificationH04W40/02, H04L45/26, H04L45/127, H04W52/46
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